Non-staining chlorophyll preparations



2,783,182 NON-STAINING cHLonoPHYLL PREPARATIONS Manno Fredrick Nelson, In, Madison, N. 3., assignor to Colgate-Palmolive Company, a corporation of Delaware No Drawing. Application February 24, 1953, Serial No. 338,607

3 (Jlaims. (Cl. 167-03) The present invention relates to novel preparations comprising in combination a chlorophyll compound and polyvinylpyrrolidone, as hereinafter described and claimed.

Chlorophyll and various derivatives thereof, such as chlorophyllins, have been employed in pharmaceutical, cosmetic and detergent compositions and various other fields of application for many years. Such materials have been proposed for many uses including Wound treatments, breath and body deodorization, as coloring agents, etc.

It may be observed that such chlorophyll compounds and the like tend to deposit or produce an undesirable stain upon suitable absorbent materials. The degree of staining power is dependent to some extent upon the amount of chlorophyll compound present and the type or nature of the composition, but the undesirable effects range from a pale green to blackish discoloration or stain. The nature of the absorbent surface is a vital factor also, and materials comprising cellulose, animal and synthetic fibers, etc, appear to be particularly susceptible to deposition of the stain. For example, use of a dental cream containing Water-soluble chlorophyllin in the ordinary or conventional manner with a tooth brush results in a greenish staining or discoloration of the tooth brush bristles which cannot be removed by ordinaryrinsing or washing of the brush. Similar staining eflects may be observed upon contact of achlorophyll compound with clothes, towels, the skin, false dentures manufactured of polyacrylic resins or the like, etc. In general, the specific nature of the stain is not known fully but such greenish stain if permitted to dry proves to be essentially waterinsoluble, even where the original chlorophyll compound was a water-soluble chlorophyllin material. Washing of the dried and stained surfaces with an aqueous detergent solution such as a soap solution does not aid materially in the removal of such characteristic stains. It

is obvious thatsuch undesirable staining effects repretherein a water-soluble polyvinylpyrrolidone having an average molecular weight from about 5,000 to 500,000 in an amount up to 10% by weight as an anti-staining agent, the ratio of said polyvinylpyrrolidone to, said chlorophyll being at least about 1:1 by weight and sufficient to inhibit the staining of the absorbent surface by the chlorophyll. A preferred embodiment of the present invention relates to a dentifrice comprising at least about 20% of polishing material, up to 5% by weight of tates Patent 0 an organic detergent, about .001 to 5% by Weight of a water-soluble chlorophyll compound or chlorophyllin normally tending to stain or discolor absorbent materials and up to 5% by weight and having an average molecular weight of 10,000 to 300,000 of a water-soluble polyvinylpyrrolidone as an anti-staining agent. Various other preferred embodiments will be apparent in the following description.

Polyvinylpyrrolidone has received some degree of recognition in blood plasma therapy. It is usually prepared by polymerizing N-vinylpyrrolidone (monomer) molecules. in known manner to any desired molecular weight or degree of polymerization. 7 Any suitable water-soluble polyvinylpyrrolidone as described, may be used in the present invention. In general, such materials are non-toxic, high molecular Weight polymers of 1 or N-vinyl 2-pyrrolidone, which are soluble in water colloidally. The specific or exact degree of polymerization is not believed critical provided'the desired Water-solubility and non-toxic effects are maintained since the productsusually comprise a mixture of specific polymers each containing a diiferent number of monomer units, depending upon the, manner and degree of polymerization, fractionation, if any, etc. The stain inhibiting eificacy of the product, moreover, is an observable phenomenon and readily determinable by simple procedures in view of the present invention.

In general, suitable polymers having an average molecular weight within the range of about 5,000 to about 500,000 should be employed in the present invention. It will generally be desirable to use products having an average molecular weight of about 10,000 to 300,000, and usually about 10,000 to 150,000. Excellent. desired effects have been obtained withpolymers of average molecular Weight within the range of about 20,000 to about 100,000, with optimum results usually at a range of about 25,000 to about 60,000. Further specific suitable examples are polymers having an, average molecular weight of about 20,000, 27,000, 30,000, 40,000, 100,000, 150,000, and 200,000, etc.

The invention is applicable to any chlorophyll composition containing the same which normally exhibits a tendency to stain a suitable absorbent (or adsorbent) surface. This has reference to chlorophyll compositions which stain the absorbent surface upon mere contact and to compositions such as powders, etc., which normally exhibit some staining tendency after contact with water or other suitable solvent or liquid medium. The term chlorophyll is used herein generically, as inclusive of the natural chlorophyll material per se, the various oilsoluble andwater-soluble chlorophyll materials and derivatives thereof, etc. Included among the fat-soluble or oil-soluble chlorophylls are the green pigmnts chlorophyll a, chlorophyll b and mixtures thereof which are usually present in nature and products of commercial manufacture. The structures of these materials have been extensively investigated and, in essence, such chlorophyll molecules are pyrolle pigments containing phytyl and methyl ester groups and magnesium bound in a complex linkage in a prophyrin system. Variou derivatives thereof may be formed in known manner. For example, the displacement of the magnesium by hydrogen or other metals such as copper, iron or nickel results in compounds known as pheophytins. Other derivatives includes pheophorbides and chlorophyllides such as are obtained by replacement of the phytyl group by an ethyl radical.

It is preferred to use chlorophyllin or water-soluble its admixture with polyvinylpyrrolidone. These watersoluble derivatives may be synthesized from the oil-soluble. forms in know manner, such as by saponification 3 with alkali to form a water-soluble salt. Suitable examples are sodium copper chlorophyllin, potassium copper chlorophyllin, sodium magnesium chlorophyllin, sodium nickel chlorophyllin, sodium iron chlorophyllin, sodium potassium copper chlorophyllin and potassium magnesium chlorophyllin.

The polyvinylpyrrolidone and chorophyll exert their beneficial functions in widely variable proportions depending upon the specific nature of the polymer, the chlorophyll compound and the type of composition. The vinylpyrrolidone polymer may be admixed with the chlorophyll in any suit-able manner and type of composition which permits the polymer to exert the desired anti-staining effects. The amount of vinylpyrrolidone polymer required to inhibit or prevent discoloration is readily determinable and the effects are, to some extent, proportional to the amount of polymer added compared to a constant amount of chlorophyll up to an optimum efiect. In general, it has been found that substantial stain-inhibiting effects are obtained usually when the minimum ratio of polyvinylpyrrolidone to chlorophyll is at least about 1:1 by weight. Greater quantities of the anti-staining agent may, of course, be used provided a sufficient amount is incorporated to inhibit the otherwise normally occurring staining effects. A ratio of this polymer to chlorophyll of 50:1 by weight has been found to produce excellent results also.

The mechanism of interaction of the polyvinylpyrrolidone with chlorophyll to inhibit the staining tendency is not understood at the present time. effects appear most pronounced when the water-soluble polyvinylpyrrolidone in suflicient amount is dissolved or dispersed in an aqueous (including aqueous-containing) vehicle or carrier such as a dental cream and is, therefore, in intimate contact with water-soluble chlorophyll in the same medium. Such a composition does not produce a noticeable stain on the teeth or on toothbrushes, Whether the latter are composed of natural fibers or of plastic bristles of varying hardnesses. It will not produce any significant stain upon artificial dentures also. It may produce a mild discoloration upon cotton, wool and nylon but the stain will readily wash out even where such stain has been permitted to dry or harden. The unusual action of polyvinylpyrrolidone appears to be primarily preventative in character and thus it is considered essential that the polymer be present simultaneously with the chlorophyll. These impoved results are possible also where oil-soluble chlorophyll is employed in contact with the polyvinylpyrrolidone.

In accordance with the present invention, novel compositions comprising chlorophyll and polyvinylpyrrolidone may be prepared and marketed in any desired form including liquid, semi-solid and solid form. Among such preparations are powders, solutions, suspensions, emulsions, salves, ointments, creams, pastes, lotions, .tablets, and the like. Such preparations may contain various adjuvant materials in suitable amounts provided the same do not substantially adversely affect the improved results produced by the mixture of chlorophyll and polyvinylpyrrolidone. Such optional added ingredients include suitable perfumes and flavoring oils, sweetening agents, preservatives, emulsifying and solubilizing agents, hydrophobic and hydrophilic ingredients or vehicles, and other materials in use in cosmetic (including pharmaceutical) preparations. Among suitable materials are glycerine, sodium benzoate, castor oil, lanolin, acetone, alcohol, fatty acid monoand di-ester of polyhydric alcohols, sodium chloride, etc.

If desired, the compositions may comprise chiefly the two essential ingredients. Thus, the polyvinylpyrrolidone in the form of powder, solutions or suspensions may be admixed in any suitable proportions with the solid, liquid or semi-solid concentrates of chlorophyll of varying purity which are produced by commercial manufacture. An illustrative technical or commercial product is sodium The desirable a'a'sansav h copper chlorophyllin or potassium sodium copper chlorophyllin prepared as a granular solid containing various impurities and which may be dissolved in water in amounts up to about 15% by weight depending upon purity. Commercial oil-soluble chlorophyll products are prepared usually in liquid or solution form in amounts up to about 15 concentration also.

It is an embodiment of the present invention that these novel mixtures of chlorophyll and polyvinylpyrrolidone may be utilized in preparations designed for application in the mouth. Such oral or dentifrice preparations include suitable tooth powders, dental creams, tooth pastes, liquid dentifrices, mouth washes or rinses, tablets, etc. The amounts of these ingredients are widely variable relative to the balance of the oral compositions. The specific amounts will vary, naturally, depending upon the type of composition, e. g., dental cream, liquid or powder, and the specific effects desired. In general, the chlorophyll and polyvinylpyrrolidone will each be a minor amount or proportion by weight of the total composition. The chlorophyll should be present in any suitable amount such as from about .001 up to about 10% by weight whereas the polyvinylpyrrolidone may be utilized in amounts up to about 10% by weight in a suitable non-toxic carrier or vehicle. In the case of tooth powders, dental creams and the like, the polyvinylpyrrolidone and chlorophyll will be preferably up to about 5% by weight of the finished formulation. Each of these essential ingredients may be incorporated in the composition in any suitable manner, such as in the form of powders, solutions, suspensions, etc.

Any suitable practically water-insoluble polishing agent may be admixed with these novel compounds in the preparation of dentifrice compositions of the present invention. There is a relatively large number of such materials known in the art. Representative materials include, for example, calcium carbonate, dicalcium phosphate (anhydrous or hydrated), tricalcium phosphate, insoluble sodium metaphosphate, aluminum hydroxide, magnesium carbonate, calcium sulfate, bentonite, etc., including suitable mixtures thereof. It is preferred to use the Water-soluble calcium and magnesium salts as the polishing agents, and, more particularly, calcium carbonate and/or a calcium phosphate. In general, these polishing agents will comprise a major proportion by weight of the solid ingredients. The polishing agent content is variable, but will generally be up to about by Weight of the total composition. In the case of a dental cream such polishing agents will generally be about 20-75% whereas in tooth powders, the polishing agents will usually be a major proportion, such as about 7095%.

In the preparation of tooth powders, it is usually sufficient to mechanically admix the various ingredients. In dental cream formulations, the liquids and solids should necessarily be proportioned to form a creamy mass of desired consistency which is extrudible from a collapsible aluminum orlead tube. In general, the liquids in the dental cream will comprise chiefly water, glycerine, sorbitol, propylene glycol, etc., including "suitable mixtures thereof. It is usually advantageous to use a mixture of both water and a hnmectant or hinder such as glycerine, sorbitol, etc. The total liquid content will generally be about 20-75% by weight of the formulation.

If desired, there may be included advantageously in such preparations a suitable surface-active agent, such as wetting agents or preferably a water-soluble detergent compound to yield added foaming power and other surface-active properties, such surface active agents being usually characterized by having a long aliphatic chain in the molecule and a water-solubilizing group. It is preferred to use an anionic organic detergent in admixture with the essential ingredients. Such detersive agents are known and include, for example, the water-soluble salts ease-tee of higher fatty acid monoglyceridemonosulfate detergent (e. g., sodium salt of monosulfated monoglycerides of higher fatty acids of coconut oil), higher fatty acid amide of amino carboxylic acid (e. g., sodium N-lauroyl sare coside), higher alkyl sulfate detergent (e. g., sodium lauryl sulfate), alkyl aryl sulfonate detergent (e, g., sodium dodecyl benzene sulfonate), higher alkyl sulfoacetate (e. g., sodium lauryl sulfoacetate), the conventional soaps of animal or vegetable fatty materials which are water-soluble salts of higher fatty acids (e. g., sodium soaps of coconut oil fatty acids), etc. In general, these detersive agents may be used in any suitable amount, such as up to about 20 and usually up to by weight. In the case of non-soap or synthetic detergents they will be employed usually in an amount up to about 5% by weight.

Other adjuvant materials are usually incorporated in suitable amounts, particularly in dental creams. It is preferred to use a gelling agent such as the natural and synthetic gums and gum-like materials, e. g., Irish moss, gum tragacanth, sodium carboxymethylcellulose, starch, etc., usually in an amount up to 10% by weight of the dental cream, and preferably from 0.55%. Furthermore, such materials as soluble saccharin, flavoring oils (e. g., oils of spearmint, peppermint), preservatives, alcohol, etc., may be used as desired in proper amount.

Mouth washes or rinses are also within the scope of the present invention. Such products are usually an effective amount of detergent or antiseptic dissolved or dispersed in a suitably flavored liquid vehicle, preferably aqueous alcoholic vehicle in which may be incorporated suitable amount of polyvinylpyrrolidone and chlorophyllin. The alcohol concentration may vary depending on the mouth eflect desired, such as about 5-70% alcohol, and preferably 540%. Liquid dentifrices are also included, such productsvusually containing a minor amount of detergent, usually dis-solved or dispersed inan aqueous alcoholic vehicle, preferably containing a mucilaginous material and optionally combined with small amounts of polishing agent, glycerine, coloring and flavoring materials.

The pH of the final formulations of the present invention is variable and, therefore, the products may have any suitable pH value in solution compatible with the stability of the materials. Where reference is made to pH values it has reference to the pH as determined on a liquid product per se, and in the case of a dental cream or power or similar product as determined on a aqueous slurry or mixture of said cream or powder. Thus, it is generally desired that the pH of the product under the testing conditions indicated be from about 5 up to about 10, and preferably from' about 5.5 to 9, with optimum desired effects at a substantially neutral pH value in solution, e. g., about 6 to 8.

The following specific examples are further illustrative of the nature of the present invention, but it is.to be understood that the invention is not limited thereto. All amounts of the various ingredients are by weight unless otherwise specified.

Example I A dental cream is prepared in the usual manner according to the following formulation:

. Percent Polyvinylpyrrolidone (av. m. w. 40,000) 0.5 Sodium copper chlorophyllin 0.1 Dicalcium phosphate dihydrate 48.25 Glycerine 28.2 Detergent; 3.75 Tetrasodium pyrophosphate 1.0

and the balance being primarily water with minor amounts of flavor, sweetening agent, gum, preservative, etc. The detergent is a sodium salt of monoglyceride monosulfates of higher fatty acids derived from coconut oil.

6 jThis dental cream upon use with a toothbrush in the usual manner does not leave any visible stain on the teeth or on the toothbrushbristles. Upon application to cotton, wool, nylon and similar materials, there is sometimes produced a mild discoloration which may be washed out readily from the material.

Example II To separate portions of a commercial chlorophyllcontaining dental cream comprising about 45% polishing agent, a minor amount 'of detergent and about 0.1% sodium copper chlorophyllin, there is added said polyvinylpyrolidone in powder form in 0.5%, 1 and 2% concentrations by weight respectively. Each portion of the cream was stirred to homogeneously disperse the polyvinylpyrrolidone therein. These creams were admixed with water to form an aqueous slurry, filtered and cotton swatches were added to the filtrate after which the swatches were dried and washed in a soap solution. The cloth treated'with the cream containing 2% polyvinylpyrrolidone had practically no stain at all whereas the creams containing lesser amounts of this polymer .possessed very mild and light stains. in comparison thereto, .a portion of the chlorophyll-containing cream which does not contain any polyvinylpyrrolidone exhibited a moderately severe greenish stain.

Similar improved results may be obtained using materials other than cotton, such as wool, nylon, rayon, silk and muslin.

Example III One half of an artificial denture containing polyacrylic resin as the base plate is brushed with a wet toothbrush containing a similar chlorophyll-containing dental cream having 0.5% of said polyvinylpyrrolidone. After cleaning with this cream, this portion of the denture exhibits no chlorophyll stain whereas identical treatment with a similar composition free of polyvinylpyrrolidone on the remaining half of the denture results in the deposition of a greenish stain.

Example IV A solution of .0l% oil-soluble chlorophyll in mineral oil is prepared to which is added 1% of said polyvinylpyrrolidone. A cotton swatch is dipped in the solution for 10 minutes and removed therefrom, resulting in a light green stain on the cloth. This swatch is then rinsed and washed in a detergent solution for several minutes resulting in substantially complete removal of any stain. Under identical treatment, the use of a chlorophyll solution which does not contain the vinylpyrrolidone polymer resultsin a deep penetrating green stain on the cotton swatch which is not removed to any significant extent by washing.

Similar results are obtained using oil-soluble chlorophyll oil in oily bases other than the mineral oil solvent. The following formulations which may be prepared in the usual manner are also productive of the desired results:

Example V.-Dental cream Sodium coconut monoglyceride monosulfateun n 4.0

- v Percent Polyvinylpyrrolidone (as described) 3.0 Sodium copper chlorophyllin 0.1 Soluble saccharin 0.2 Flavor, q. 5.

Example VlL-Mouth wash Percent Sodium copper chlorophyllin 0.1 Polyvinylpyrrolidone (as described) 0.5 Wetting agent 1.0 Flavor 0.2 Saccharin 0.02 Ethyl alcohol 15.0 Water, q. s.

Example VIlI.--Liquid dentifrice Percent Sodium copper chlorophyllin 0.05 Polyvinylpyrrolidone (as described) 10.0 Detergent 9.0 Irish moss gum 1.25 Ethyl alcohol 10.0 Soluble saccharin 0.5 Flavor 3.0 Water, q. s.

Although the present invention has been described with reference to particular embodiments and examples, it will be apparent to those skilled in the art that variations and modifications of this invention can be made and that equivalents can be substituted therefor without departing from the principles and true spirit of the invention.

Having thus described the invention what is claimed is:

1. A chlorophyll-containing composition normally tending to deposit a greenish stain on an absorbent surface comprising chlorophyll in an amount from .001 to 10% by weight in a non-toxic carrier, and having incorporated therein a water-soluble polyvinylpyrrolidone having an average molecular weight from about 5,000 to 500,000 in. an amount up to 10% by weight as an antistaining agent, the ratio of said polyvinylpyrrolidone to said chlorophyll being at least about 1:1 by weight and sufiicient to inhibit the staining of the absorbent surface by the chlorophyll.

2. A composition in accordance with claim 1 containing chlorophyllin and water-soluble polyvinylpyrrolidone having an average molecular weight of about 10,000 to 300,000 in an aqueous carrier.

3. A dentifrice composition comprising at least about 20% by weight of polishing material, up to 5% by weight of an organic detergent, about .001 to 5% by weight of chlorophyllin normally tending to deposit a greenish stain on an absorbent surface, and up to 5% by weight of a water-soluble polyvinylpyrrolidone having an average molecular weight of 10,000 to 300,000, the ratio of said polyvinylpyrrolidone to said chlorophyllin being at least about 1:1 by weight and sufficient to inhibit the staining of the absorbent surface by the chlorophyllin.

References Cited in the file of this patent FOREIGN PATENTS 601,801 Great Britain May 12, 1948 OTHER REFERENCES PVPI Gen. Aniline & Film Corp. Devel. Dept, New York, 1951, page 157, article 225.

Sperandio: Chlorophyll, Bull. Amer. Hosp. Pharmacists, vol. 8, No. 5, October 1951, pages 292-297 (page 294 pertinent), l67-65F. 

3. A DENTIFRICE COMPOSITION COMPRISING AT LEAST ABOUT 20% BY WEIGHT OF POLISHING MATERIAL, UP TO 5% BY WEIGHT OF AN ORGANIC DETERGENT, ABOUT .001 TO 5% BY WEIGHT OF CHLOROPHYLLIN NORMALLY TENDING TO DEPOSIT A GREENISH STAIN ON AN ABSORBENT, SURFACE, AND UP TO 5% BY WEIGHT OF A WATER-SOLUBLE POLYVINYLPYRROLIDONE HAVING AN AVERAGE MOLECULAR WEIGHT OF 10,000 TO 300,000, THE RATIO OF SAID POLYVINYLPYRRLIDONE TO SAID CHLOROPHYLIN BEING AT LEAST ABOUT 1:1 BY WEIGHT AND SUFFICIENT TO INHIBIT THE STAINING OF THE ABSORBENT SURFACE BY THE CHLOROPHYLLIN. 